3H-Eunicin acetate synthesized from 3H-acetoxyphthalimide was used in a filtration assay to measure specific binding to membranes from Torpedo Californica. These membrane preparations showed high non-specific binding and are undergoing more rigorous purification steps. In addition, other cembranoids and relevant labelling chemistry is being evaluated: Option 1: pseudoplexauric acid and 3H-methanol -> 3H pseudoplexauric methyl ester Option 2: pseudoplexauric acid methyl ester + 3H-Diazomethane -> 3H-cyclopropyl pseudoplexauric acid methyl ester